The present invention relates to an image processing apparatus and, particularly, to such an apparatus which can easily define image regions corresponding to each other in a plurality of images or image regions corresponding to each other in an image as regions of interest using the same figure.
There is known a radiation diagnosis system comprising the steps of employing, as a detecting material for the radiation, a stimulable phosphor which can absorb and store the energy of radiation upon being irradiated therewith and release a stimulated emission whose amount is proportional to that of the received radiation upon being stimulated with an electromagnetic wave having a specific wavelength range, storing and recording the energy of radiation transmitted through an object in the stimulable phosphor contained in a stimulable phosphor layer formed on a stimulable phosphor sheet, scanning the stimulable phosphor layer with an electromagnetic wave to excite the stimulable phosphor, photoelectrically detecting the stimulated emission released from the stimulable phosphor to produce digital image signals, effecting image processing on the obtained digital image signals, and reproducing an image on displaying means such as a CRT or the like or a photographic film (see, for example, Japanese Patent Application Laid Open Nos. 55-12429, 55-116340, 55-163472, 56-11395, 56-104645 and the like).
There is also known an autoradiographic image detection system comprising the steps of employing a similar stimulable phosphor as a detecting material for the radiation, introducing a radioactively labeled substance into an organism, using the organism or a part of the tissue of the organism as a specimen, placing the specimen and a stimulable phosphor sheet formed with a stimulable phosphor layer together in layers for a certain period of time, storing and recording radiation energy in a stimulable phosphor contained in the stimulable phosphor layer, scanning the stimulable phosphor layer with an electromagnetic wave to excite the stimulable phosphor, photoelectrically detecting the stimulated emission released from the stimulable phosphor to produce digital image signals, effecting image processing on the obtained digital image signals, and reproducing an image on displaying means such as a CRT or the like or a photographic film (see, for example, Japanese Patent Publication No. 1-60784, Japanese Patent Publication No. 1-60782, Japanese Patent Publication No. 4-3952 and the like).
There is further known a chemiluminescent image detection system using as a detecting material for detecting light a stimulable phosphor which can absorb, store and record the light energy when it is irradiated with light and which, when it is then stimulated by an electromagnetic wave having a specified wavelength, can release stimulated emission whose light amount corresponds to the amount of light radiation with which it was irradiated, which comprises the steps of selectively labeling a fixed high molecular substance such as a protein or a nucleic acid sequence with a labeling substance which generates chemiluminescent emission when it contacts a chemiluminescent substance, contacting the high molecular substance selectively labeled with the labeling substance and the chemiluminescent substance, photoelectrically detecting the chemiluminescent emission in the wavelength of visible light generated by the contact of the chemiluminescent substance and the labeling substance and producing digital image signals, effecting image processing thereon, and reproducing a chemiluminescent image on a display means such as a CRT or a recording material such as a photographic film, thereby obtaining information relating to the high molecular substance such as genetic information (see, for example, U.S. Pat. No. 5,028,793, British Patent Publication GB No. 2,246,197A and the like).
There are further known an electron microscopic image detection system and a radiographic diffraction image detection system comprising the steps of employing, as a detecting material for an electron beam or radiation, a stimulable phosphor which can absorb and store the energy of an electron beam or radiation upon being irradiated therewith and release a stimulated emission whose amount is proportional to that of the received electron beam or radiation upon being stimulated with an electromagnetic wave having a specific wavelength range, irradiating a metal or nonmetal specimen with an electron beam and effecting elemental analysis, composition analysis or structural analysis of the specimen by detecting a diffraction image or a transmission image, or irradiating the tissue of an organism with an electron beam and detecting an image of the tissue of the organism, or irradiating a specimen with radiation, detecting a radiographic diffraction image and effecting structural analysis of the specimen (see, for example, Japanese Patent Application Laid Open No. 61-51738, Japanese Patent Application Laid Open No. 61-93538, Japanese Patent Application Laid Open No. 59-15843 and the like).
Unlike the system using a photographic film, according to these systems using the stimulable phosphor as a detecting material for an image, development, which is chemical processing, becomes unnecessary. Further, it is possible reproduce a desired image by effecting image processing on the obtained image data and effect quantitative analysis using a computer. Use of a stimulable phosphor in these processes is therefore advantageous.
On the other hand, a fluorescence system using a fluorescent substance as a labeling substance instead of a radioactively labeling substance in the autoradiographic image detecting system is known. According to this system, it is possible to study a genetic sequence, study the expression level of a gene, and to effect separation or identification of protein or estimation of the molecular weight or properties of protein or the like. For example, this system can perform a process including the steps of distributing a plurality of DNA fragments on a gel support by means of electrophoresis after a fluorescent dye was added to a solution containing a plurality of DNA fragments to be distributed, or distributing a plurality of DNA fragments on a gel support containing a fluorescent dye, or dipping a gel support on which a plurality of DNA fragments have been distributed by means of electrophoresis in a solution containing a fluorescent dye, thereby labeling the electrophoresed DNA fragments, exciting the fluorescent dye by a stimulating ray to cause it to release fluorescent light, detecting the released fluorescent light to produce an image and detecting the distribution of the DNA fragments on the gel support. This system can also perform a process including the steps of distributing a plurality of DNA fragments on a gel support by means of electrophoresis, denaturing the DNA fragments, transferring at least a part of the denatured DNA fragments onto a transfer support such as a nitrocellulose support by the Southern-blotting method, hybridizing a probe prepared by labeling target DNA and DNA or RNA complementary thereto with the denatured DNA fragments, thereby selectively labeling only the DNA fragments complementary to the probe DNA or probe RNA, exciting the fluorescent dye by a stimulating ray to cause it to release fluorescent light, detecting the released fluorescent light to produce an image and detecting the distribution of the target DNA on the transfer support. This system can further perform a process including the steps of preparing a DNA probe complementary to DNA containing a target gene labeled by a labeling substance, hybridizing it with DNA on a transfer support, combining an enzyme with the complementary DNA labeled by a labeling substance, causing the enzyme to contact a fluorescent substance, transforming the fluorescent substance to a fluorescent substance having fluorescent light releasing property, exciting the thus produced fluorescent substance by a stimulating ray to release fluorescent light, detecting the fluorescent light to produce an image and detecting the distribution of the target DNA on the transfer support. This fluorescence detecting system is advantageous in that a genetic sequence or the like can be easily detected without using a radioactive substance.
It is often required for such systems to define image regions corresponding to each other in a plurality of images of encephalon slices of a test mouse displayed on a display means such as a CRT as regions of interest using the same figure or define spots corresponding to each other in different lanes in an electrophoresis image as regions of interest using the same figure.
In these cases, conventionally the only way available to the user is to view the screen of a CRT or the like and draw a figure so as to surround corresponding image regions, thereby defining regions of interest, and it is extremely difficult to define image regions corresponding to each other in a plurality of images or image regions corresponding to each other in an image as regions of interest using the same figure.
It is therefore an object of the present invention to provide an image processing apparatus which can easily define image regions corresponding to each other in a plurality of images or image regions corresponding to each other in an image as regions of interest using the same figure.
The above other objects of the present invention can be accomplished by an image processing apparatus comprising a temporary memory means for two-dimensionally mapping and temporarily storing image data containing image region data corresponding to at least two image regions having a similar shape and stored in an image data storing means, a display means for reproducing images based on the image data stored in the temporary memory means, an interest region defining means for defining a region of interest in one of the at least two image regions having a similar shape displayed on the display means, a pixel specifying means for specifying at least one first reference pixel in the one of the at least two image regions having a similar shape and specifying a second pixel corresponding to the first reference pixel in at least one image region other than the one of the at least two image regions, a copy means for copying the region of interest defined by the interest region defining means and the at least one first reference pixel specified by the pixel specifying means, a template matching means for effecting template matching between minute region image data corresponding to a minute region containing the coordinate value of the at least one first reference pixel as a center coordinate value and minute region image data corresponding to a minute region containing the coordinate value of the at least one second reference pixel corresponding to the at least one first reference pixel as a center coordinate value, and an affine conversion means for effecting an affine conversion on image data corresponding to an outer periphery of the region of interest stored in the temporary memory means based on the result of the template matching made by the template matching means.
According to the present invention, image regions corresponding to each other in a plurality of images or image regions corresponding to each other in an image can be defined as regions of interest using the same figure merely by copying the region of interest defined in the one image and the at least one first reference pixel into the other image, and effecting template matching between minute region image data corresponding to a minute region containing the coordinate value of the at least one first reference pixel as a center coordinate value and minute region image data corresponding to a minute region containing the coordinate value of the at least one second reference pixel as a center coordinate value.
Further, according to the present invention, even when image data have been produced based on a plurality of images rotated relatively to each other, image regions corresponding to each other in a plurality of images or image regions corresponding to each other in an image can be defined as regions of interest using the same figure by specifying two or more first reference pixels in an image, copying them onto the other image, and effecting template matching between minute region image data corresponding to a minute region containing the coordinate values of the two or more first reference pixels as center coordinate values and minute region image data corresponding to a minute region containing the coordinate values of two or more second reference pixels as center coordinate values.
In a preferred aspect of the present invention, the image data are data produced from the same object under different conditions.
In another preferred aspect of the present invention, the image data are data produced from different objects.
In a further preferred aspect of the present invention, the image data are data produced using a stimulable phosphor sheet.
In a further preferred aspect of the present invention, the image data are selected from the group consisting of radiation data of an object, autoradiographic image data, radiographic diffraction image data, electron microscope image data and chemiluminescent image data.
In a further preferred aspect of the present invention, the image data consist of fluorescent image data.
In the present invention, the stimulable phosphor usable for producing radiation image data of an object, autoradiographic image data, radiographic diffraction image data or electron microscope image data may be of any type insofar as it can store radiation energy or electron beam energy and can be stimulated by an electromagnetic wave to release the radiation energy or the electron beam energy stored therein in the form of light. More specifically, preferably employed stimulable phosphors include alkaline earth metal fluorohalide phosphors (Ba1xe2x88x92x, M2+x)FX:yA (where M2+ is at least one alkaline earth metal selected from the group consisting of Mg, Ca, Sr, Zn and Cd; X is at least one element selected from the group consisting of Cl, Br and I, A is at least one element selected from the group consisting of Eu, Tb, Ce, Tm, Dy, Pr, He, Nd, Yb and Er; x is equal to or greater than 0 and equal to or less than 0.6 and y is equal to or greater than 0 and equal to or less than 0.2.) disclosed in U.S. Pat. No. 4,239,968, alkaline earth metal fluorohalide phosphors SrFX:Z (where X is at least one halogen selected from the group consisting of Cl, Br and I; Z is at least one Eu and Ce.) disclosed in Japanese Patent Application Laid Open No. 2-276997, europium activated complex halide phosphors BaFXxNaXxe2x80x2:aEu2+ (where each of X or Xxe2x80x2 is at least one halogen selected from the group consisting of Cl, Br and I; x is greater than 0 and equal to or less than 2; and y is greater than 0 and equal to or less than 0.2.) disclosed in Japanese Patent Application Laid Open No. 59-56479, cerium activated trivalent metal oxyhalide phosphors MOX:xCe (where M is at least one trivalent metal selected from the group consisting of Pr, Nd, Pm, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb and Bi; X is at least one halogen selected from the group consisting of Br and I; and x is greater than 0 and less than 0.1.) disclosed in Japanese Patent Application laid Open No. 58-69281, cerium activated rare earth oxyhalide phosphors LnOX:xCe (where Ln is at least one rare earth element selected from the group consisting of Y, La, Gd and Lu; X is at least one halogen selected from the group consisting of Cl, Br and I; and x is greater than 0 and equal to or less than 0.1.) disclosed in U.S. Pat. No. 4,539,137 and europium activated complex halide phosphors MIIFXaMIXxe2x80x2bMxe2x80x2IIXxe2x80x32cMIIIXxe2x80x2xe2x80x33xA:yEu2+ (where MII is at least one alkaline earth metal selected from the group consisting of Ba, Sr and Ca; MI is at least one alkaline metal selected from the group consisting of Li, Na, K, Rb and Cs; Mxe2x80x2II is at least one divalent metal selected from the group consisting of Be and Mg; MIII is at least one trivalent metal selected from the group consisting of Al, Ga, In and Ti; A is at least one metal oxide; X is at least one halogen selected from the group consisting of Cl, Br and I; each of Xxe2x80x2, Xxe2x80x3 and Xxe2x80x2xe2x80x3 is at least one halogen selected from the group consisting of F, Cl, Br and I; a is equal to or greater than 0 and equal to or less than 2; b is equal to or greater than 0 and equal to or less than 10xe2x88x922; c is equal to or greater than 0 and equal to or less than 10xe2x88x922; a+b+c is equal to or greater than 10xe2x88x922; x is greater than 0 and equal to or less than 0.5; and y is greater than 0 and equal to or less than 0.2.) disclosed in U.S. Pat. No. 4,962,047.
In the present invention, the stimulable phosphor employed for producing a chemiluminescent image data may be of any type insofar as it can store the energy of light having a visible light wavelength and can be stimulated by an electromagnetic wave to release the energy of light having a visible light wavelength stored therein in the form of light. However, a stimulable phosphor which can be stimulated by light having a visible light wavelength is preferably employed. More specifically, preferably employed stimulable phosphors include metal halophosphates, rare-earth-activated sulfide-host phosphors, aluminate-host phosphors, silicate-host phosphors and fluoride-host phosphors disclosed in UK Patent Application 2,246,197 A. Among these listed phosphors, rare-earth-activated sulfide-host phosphors are preferable and rare-earth-activated alkaline earth metal sulfide-host phosphors disclosed in U.S. Pat. Nos. 5,029,253 and 4,983,834 are particularly preferable.